The invention relates to a directional gyro, comprising a first gimbal mounted in a frame by means of an essentially vertical axis, a second gimbal whose axis is mounted at a right angle to the essentially vertical axis in the first gimbal, a gyromotor including a stator and a rotor and being arranged in the second gimbal in such a manner that the spin axis is perpendicular to the axis of the second gimbal, a vertically device for putting the spin axis in a horizontal orientation and a pickup for indicating the course angle.
Such a directional gyro is disclosed in "Grammel-Der Kreisel II", pages 189 et seq. That gyro includes a gryo case which is mounted in the gimbal ring by means of horizontal pins and with its spin axis as horizontal as possible.
This gimbal ring itself is mounted in a fixed frame to be rotatable on vertical pins. In order to compensate for the seeming drift of the gyro, a supporting motor is disposed at the horizontal axis and at the vertical axis. By means of a verticality sensor, the supporting motor at the vertical axis is excited whenever the spin axis of the gyro leaves the horizontal position. The supporting motor at the horizontal axis serves to adjust the gyro about its vertical axis. The verticality sensors are pendulums fastened to the gimbal frame and equipped with electrical pickups, electrolyte sensors, round spirit levels or capacitive verticality sensors.
It is evident that this gyro requires high structural expenditures to provide sufficiently accurate course information. Moreover, a plurality of components are required to support and adjust the gyro, such as, for example, verticality sensors, servomotors, follow-up circuits.